HTML

Ref

HTML 教程wangdoc.com

HTML Intro

• block elements: take a whole line.

• inline elements: no new line.

Tags are case insensitive. <img> is the same as <IMG>.

Attributes are case insensitive. onclick is the same as onClick. Usually values are in double quotes.

HTML ignores indentation and newlines.

<title>My Blog</title>

is the same as

<title>
    My Blog
</title>

<!-- 这是一个注释 -->
<!--
  <p>hello world</p>
-->

Browser combines multiple whitespaces, \t, \n, \r.

<p>hello      world</p>
is the same as
<p>hello world</p>

<meta>

<meta charset="utf-8">
<meta name="key" content="value">

URL Intro

18 characters are reserved: they can only appear at certain places in URL. If those characters are used elsewhere in URL, they need to be escaped (% + ASCII code). Encoding other characters are not recommended.

• space：%20

• !：%21

• #：%23

• $：%24

• &：%26

• '：%27

• (：%28

• )：%29

• *：%2A

• +：%2B

• ,：%2C

• /：%2F

• :：%3A

• ;：%3B

• =：%3D

• ?：%3F

• @：%40

• [：%5B

• ]：%5D

Other characters (not reserved, not legal) will be encoded to UTF-8 by browser (汉字).

encodeURIComponent() - JavaScript | MDNMDN Web Docs

Attributes

<p id="p1" class="big bright"></p>
<div title="版权说明">
  <p>本站内容使用创意共享许可证，可以自由使用。</p>
</div>
title will be shown as a tooltip when hovered.

data- attributes can be used by CSS or JavaScript. CSS example:

/* HTML 代码如下
<div data-role="mobile">
Mobile only content
</div>
*/
div[data-role="mobile"] {
  display:none;
}

/* HTML 代码如下
<div class="test" data-content="This is the div content">test</div>​
*/
.test {
  display: inline-block;
}
.test:after {
  content: attr(data-content);
}

event handler: values are JavaScript code. Keys:

onabort, onautocomplete, onautocompleteerror, onblur, oncancel, oncanplay, oncanplaythrough, onchange, onclick, onclose, oncontextmenu, oncuechange, ondblclick, ondrag, ondragend, ondragenter, ondragexit, ondragleave, ondragover, ondragstart, ondrop, ondurationchange, onemptied, onended, onerror, onfocus, oninput, oninvalid, onkeydown, onkeypress, onkeyup, onload, onloadeddata, onloadedmetadata, onloadstart, onmousedown, onmouseenter, onmouseleave, onmousemove, onmouseout, onmouseover, onmouseup, onmousewheel, onpause, onplay, onplaying, onprogress, onratechange, onreset, onresize, onscroll, onseeked, onseeking, onselect, onshow, onsort, onstalled, onsubmit, onsuspend, ontimeupdate, ontoggle, onvolumechange, onwaiting

HTML character encoding

<p>hello</p>
<!-- 等同于 -->
<p>&#104;&#101;&#108;&#108;&#111;</p>
<!-- 等同于 -->
<p>&#x68;&#x65;&#x6c;&#x6c;&#x6f;</p>

entity: &name;

• <：<

• >：>

• "："

• '：'

• &：&

• ©：©

• #：#

• §：§

• ¥：¥

• $：$

• £：£

• ¢：¢

• %：%

• *：$ast;

• @：@

• ^：^

• ±：±

• 空格： 

HTML tags

• <header>

• <footer>

• <main>

• <article>

• <aside>

• <section>

• <nav>

• <h1> ~ <h6>

• <hgroup>

Text tags

• <br>: for inline elements

<pre>hello

   world</pre>

preformatted, keeps spaces and newline
multiline <code> has to be in <pre>
<pre>
<code>
  let a = 1;
  console.log(a);
</code>
</pre>

• <strong> <b>

• <em> <i> (emphasize)

• <sub> <sup> <var> (variable in math formula)

• <u> underline <s> strikethrough

• <blockquote> <cite> <q>

• <ins>标签是一个行内元素，表示原始文档添加（insert）的内容。<del>与之类似，表示删除（delete）的内容。它们通常用于展示文档的删改。

• <small>: no need for CSS.

• <mark>: for highlight.

• <ruby> for pinyin https://wangdoc.com/html/text.html#ruby

Table tags

• <ol>: attributes: reversed, start="5", type

  • type属性指定数字编号的样式。目前，浏览器支持以下样式。

    • a：小写字母

    • A：大写字母

    • i：小写罗马数字

    • I：大写罗马数字

    • 1：整数（默认值）

<ol type="a" start="3">
  <li>列表项 A</li>
  <li>列表项 B</li>
  <li>列表项 C</li>
</ol>

• <li>: value

<ol>
  <li>列表项 A</li>
  <li value="4">列表项 B</li>
  <li>列表项 C</li>
</ol>

Image

responsive image https://wangdoc.com/html/image.html

Link

• <a> can have mailto: as href.

• <link>: rel="stylesheet" relation

Other tags

• tables https://wangdoc.com/html/table.html

• Forms https://wangdoc.com/html/form.html

• New tags

  • <dialog>: native modal

  • <details> <summary>